1. Technical Field
Example embodiments relate generally to photo-sensing devices, and more particularly to three-dimensional image sensors and/or methods of operating three-dimensional image sensors.
2. Description of the Related Art
A photo-sensing device such as an image sensor is configured to convert optical signals for providing image information and/or depth information of an object to electrical signals. Research and development is in progress to enhance the quality of the image captured by the image sensor such as a charge-coupled device (CCD) image sensor and a complementary metal oxide semiconductor (CMOS) image sensor. In more detail, research is in progress to improve performance of a three-dimensional image sensor for providing depth information or distance information representing a distance to an object in addition to the image information of the object.
A conventional three-dimensional image sensor uses an infrared light or a near-infrared light as transmission light to obtain the depth information. Compared with color pixels for obtaining image information, depth pixels have relatively low sensitivity and signal-to-noise ratio (SNR), and thus, it is relatively difficult to obtain accurate depth information.